The present invention relates to through-wall bushings wherein a protected passage is defined through a wall or compartment for cables, pipes, and the like.
Through-wall bushings are well known in the art for providing a protected passageway for cables, wires, and any other device that must pass through a wall or other structure. Typically, these bushings comprise separate members that fit into an opening or hole defined in the wall and which clamp onto opposite sides of the wall. In one conventional embodiment of such a bushing, the separate members are threaded together and are thus threadedly tightened onto the wall structure to clamp the wall structure between opposing flanges. The male member of the pair defines the protected passageway and the other member is typically a ring member that is threadedly engaged onto the male member.
It is desirable that such bushings be used for wall structures having various thicknesses so that separate bushings need not be provided for each different wall structure. In other words, the bushings should be versatile enough to be used on varying thickness wall structures. In this regard, conventional threaded bushings are axially adjustable at least along the length of their engaging threaded portions. However, with such conventional devices, an external means or device must be provided to ensure that the bushing remains tightened relative to the wall structure and that the members will not disengage or loosen due to vibration, and the like. These external locking devices are cumbersome, often render the bushing non-reusable, and add significantly to the expense of the bushings. Additionally, it is often desirable that the bushings be manually adjustable, even after they are set initially into the wall structure. This is generally not possible with conventional bushing devices employing external locking mechanisms.
The present invention relates to an improvement in conventional threaded bushings and addresses the problems with the conventional bushings noted above.